The proposed European Telecommunications Standards Institute (ETSI) standard for Digital Mobile Radio (DMR) describes a packet data protocol. In this protocol, each packet comprises a header and defined length blocks portion carrying data (also referred to herein as “payload”). In the proposed ETSI-DMR standard, the header needs to indicate a format of the packet's payload (e.g. 24 bit addresses, 16 bit words, 8 bit words, etc.) and the padding that may be added to the packet to maintain the defined length of the block. However, there are only a limited number of bits in the header to be able to indicate the format of the packet and to indicate the padding that may be required.
One option is to increase the header size so as to accommodate the need to indicate the format of the packet and to indicate the padding that may be required. However, increasing the header size increases the length of the packet and, consequently, increases the amount of time spent using the wireless resource. Further, increasing the amount of time spent using the wireless resource may be an inefficient use of the DMR system and may lead to decreased system capacity.
Thus, there is a need for an improved method of indicating padding in a digital mobile radio system.
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